Emily C. Nacol has written a fascinating interrogation of the idea of risk, the concept of vulnerability, and the evolution of probabilistic thinking as conceived of and explored by four of the preeminent British thinkers of the seventeenth and eighteenth centuries. Nacol’s book, An Age of Risk: Politics and Economy in Early Modern Britain (Princeton University Press, 2016) examines the political, economic, and epistemological works of Thomas Hobbes, John Locke, David Hume, and Adam Smith. Each thinker’s ideas are explored in regard to the way they consider risk, which itself was a fairly new concept and had grown out of maritime concerns. An Age of Risk traces the concept itself within political thinking, and why it grows into an important dimension of the works by these theorists. Nacol explains that Hobbes, Locke, Hume, and Smith thought differently about risk and, as a result, structured their theories in distinct ways. She examines how Hobbes and Locke are generally concerned with minimizing risk, and their thinking is designed to more directly try to limit risk or alleviate the potential within political society and the economy. In the analysis of Hume’s work and of Smith’s work, Nacol finds a different approach to risk especially in Hume’s estimation that humans will inevitably have to contend with risk and uncertainty, and this leads to the consideration of political emotions like anxiety and fear. Smith, Nacol notes, moves into the realm of probabilistic thinking in his work as he integrates considerations of risk and uncertainty into his political and economic thought. All four thinkers provide lenses through which to consider this concept of vulnerability and what it means to an individual, and to political and economic orders.